Rwanda: KivuWatt transforms gas from ‘killer lake’ into electricity

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The engineers aboard the floating power station on Lake Kivu could only watch nervously as the volcano in the distance erupted violently, sending tremors rumbling through the water beneath them.

It was not the lava shooting from Mount Nyiragongo last May that spooked them, but the enormous concentrations of potentially explosive gases within Kivu, one of Africa’s Great Rift lakes lying between Rwanda and the Democratic Republic of Congo.

Flanked by rolling green hills tumbling into glassy waters, Kivu is not quite the picture of tranquility it seems to be, according to Francois Darchambeau from KivuWatt, a company that extracts gas from the lake’s waters for electricity.

Thousands of years of volcanic activities have caused a massive accumulation of methane and carbon dioxide to dissolve in the depths of
Kivu — enough to prove monumentally destructive in the rare event they were released.

If triggered, a so-called limnic eruption would cause “a huge explosion of gas from deep waters to the surface” resulting in large waves and a poisonous gas cloud that would put the lives of millions at risk, said Darchambeau, Environmental Manager at KivuWatt.

“This is what we call a killer lake,” the limnologist, or an expert in freshwater systems, told AFP.

Only three such lakes exist in the world: Kivu, Lakes Nyos, and Monoun in northwest Cameroon.

The latter two experienced limnic eruptions in the 1980s and the bigger disaster at Nyos suffocated more than 1,700 people in a toxic release of carbon dioxide.

But these catastrophes occurred in a rural area, whereas some two million people would be “at-risk” of such a similar disaster involving Kivu, said Darchambeau.

In both Rwanda and DR Congo, many live in fear of the lake’s harmful potential and stories abound of swimmers disappearing into its depths after being asphyxiated or pulled under.